Current work vehicles, such as tractors and other agricultural vehicles, include an electronically controlled engine and a transmission, such as a power shift transmission (PST) or a continuously variable transmission (CVT). CVTs generally allow for enhanced performance by providing continuous and smooth gear ratio changes. Typically, CVTs have a hydro-mechanical configuration such that power from the engine flows in parallel through both a hydrostatic branch and a mechanical branch. In addition, CVTs may include multiple speed ranges to gain finer ratio control and to extend the ground speed range. Ratio changes are made within each speed range by changing the swash plate angle of a hydraulic pump of the hydrostatic branch. Additionally, range changes within the CVT are seamless.
While the efficiency characteristics of conventional engines are relatively straight forward, the efficiencies of a CVT are much more complicated. Specifically, the required swash plate angle for a given ground speed generally varies depending on the specific range clutches engaged within the transmission. Moreover, the transmission efficiency generally varies distinctly within each range. Thus, significant differences in the operating efficiency of a CVT may be achieved for a given ground speed. In addition, the loads on other power consuming components of a work vehicle, such as the power take-off, hydraulic accessories, drive axle and/or the like, are typically complex and highly dynamic in nature. Thus, selecting the optimal operational settings in order to achieve the desired productivity and minimize fuel consumption can be quite challenging.
In current control systems, algorithms have been developed that focus solely on the engine speed control strategy. For example, engine speed is typically controlled based on the vehicle loads, with the engine running at its most efficient settings when loads are relatively low. Unfortunately, such control algorithms fail to take into account the role that other vehicle components play in impacting the overall efficiency of the vehicle.
Accordingly, a system and method for reducing the fuel consumption of a work vehicle that takes into account the operating efficiencies of the engine, transmission and various other power consuming components of the vehicle would be welcomed in the technology.